Characterization of sugarcane (Saccharum spp.) leaf senescence: implications for biofuel production.
Characterization of sugarcane (Saccharum spp.) leaf senescence: implications for biofuel production.
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DOI：
10.1186/s13068-016-0568-0
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发表时间：
2016
影响因子：
6.3
通讯作者：
Molinari HBC
中科院分区：
文献类型：
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作者：
Martins MTB;de Souza WR;da Cunha BADB;Basso MF;de Oliveira NG;Vinecky F;Martins PK;de Oliveira PA;Arenque-Musa BC;de Souza AP;Buckeridge MS;Kobayashi AK;Quirino BF;Molinari HBC
第二代乙醇（2g -生物乙醇）使用木质纤维素原料生产乙醇。甘蔗是最适合用于生物燃料生产的作物之一。它的汁液被提取出来用于制糖，而甘蔗渣、稻草和衰老的叶子被认为是工业废物。衰老是植物细胞的年龄依赖性退化，最终导致细胞死亡和植物生命周期的完成。由于衰老叶片也可用于生物燃料生产，了解自然衰老的过程，包括营养物质的再动员及其对细胞壁的影响，可以为甘蔗叶片生产2g生物乙醇提供有用的信息。对商品甘蔗品种RB867515叶片自然衰老过程进行了研究。衰老的特征是光合色素含量明显减少，N、P、K、B、Cu、Fe、Zn等营养物质的再动员，Ca、S、Mg、B、Mn、Al的积累。细胞壁组成没有发生明显变化，细胞壁相关基因的表达变化较小，表明细胞壁在衰老过程中得到了保存。衰老标记基因，如sag12样基因和xet样基因，也在甘蔗中被鉴定出来并被发现是高表达的。我们对一个健壮的甘蔗品种衰老过程中营养物质的再动员的研究有助于理解高产作物的营养平衡是如何实现的。一般来说，中性单糖谱不会随着叶片衰老而发生显著变化，这表明甘蔗衰老叶片可以作为生物燃料生产的原料，使用为非衰老叶片建立的预处理方法而无需额外的努力。在此基础上，对甘蔗品种改良的生物技术应用前景进行了展望。本文的在线版本（doi:10.1186/s13068-016-0568-0）包含补充材料，可供授权用户使用。
Second-generation ethanol (2G-bioethanol) uses lignocellulosic feedstocks for ethanol production. Sugarcane is one among the most suitable crops for biofuel production. Its juice is extracted for sugar production, while sugarcane bagasse, straw, and senescing leaves are considered industrial waste. Senescence is the age-dependent deterioration of plant cells, ultimately leading to cell death and completion of the plant life cycle. Because senescing leaves may also be used for biofuel production, understanding the process of natural senescence, including remobilization of nutrients and its effect on cell walls can provide useful information for 2G-bioethanol production from sugarcane leaves. The natural senescence process in leaves of the commercial sugarcane cultivar RB867515 was investigated. Senescence was characterized by strong reduction in photosynthetic pigments content, remobilization of the nutrients N, P, K, B, Cu, Fe, and Zn, and accumulation of Ca, S, Mg, B, Mn, and Al. No significant changes in the cell-wall composition occurred, and only small changes in the expression of cell wall-related genes were observed, suggesting that cell walls are preserved during senescence. Senescence-marker genes, such as SAG12-like and XET-like genes, were also identified in sugarcane and found to be highly expressed. Our study on nutrient remobilization under senescence in a vigorous sugarcane cultivar can contribute to the understanding on how nutrient balance in a high-yielding crop is achieved. In general, neutral monosaccharide profile did not change significantly with leaf senescence, suggesting that senescing leaves of sugarcane can be as a feedstock for biofuel production using pretreatments established for non-senescing leaves without additional efforts. Based on our findings, the potential biotechnological applications for the improvement of sugarcane cultivars are discussed. The online version of this article (doi:10.1186/s13068-016-0568-0) contains supplementary material, which is available to authorized users.